TestResponse now has unicode support. It is turned on by default
for all responses with charset information. This is backward
incompatible change if you rely (e.g. in doctests) on parsed
form fields or responses returned by json and lxml methods
being encoded strings when charset header is in response. In order
to switch to old behaviour pass use_unicode=False flag to
TestApp constructor.

Added method TestApp.request(), which can be used for
sending requests with different methods (e.g., MKCOL). This
method sends all its keyword arguments to
webtest.TestRequest.blank() and then executes the request.
The parameters are somewhat different than other methods (like
webtest.TestApp.get()), as they match WebOb’s attribute
names exactly (the other methods were written before WebOb existed).

Removed the copying of stdout to stderr during requests.

Fix file upload fields in forms (#340) – you could
upload files with webtest.TestApp.post(), but if you use
resp.form file upload fields would not work (from rcs-comp.com
and Matthew Desmarais).